<?php

/**
 * Zend Framework
 *
 * LICENSE
 *
 * This source file is subject to the new BSD license that is bundled
 * with this package in the file LICENSE.txt.
 * It is also available through the world-wide-web at this URL:
 * http://framework.zend.com/license/new-bsd
 * If you did not receive a copy of the license and are unable to
 * obtain it through the world-wide-web, please send an email
 * to license@zend.com so we can send you a copy immediately.
 *
 * @category   Zend
 * @package    Zend_Gdata
 * @subpackage App
 * @copyright  Copyright (c) 2005-2011 Zend Technologies USA Inc. (http://www.zend.com)
 * @license    http://framework.zend.com/license/new-bsd     New BSD License
 * @version    $Id: Feed.php 23775 2011-03-01 17:25:24Z ralph $
 */

/**
 * @see Zend_Gdata_App_Entry
 */
require_once 'Zend/Gdata/App/Entry.php';

/**
 * @see Zend_Gdata_App_FeedSourceParent
 */
require_once 'Zend/Gdata/App/FeedSourceParent.php';

/**
 * Atom feed class
 *
 * @category   Zend
 * @package    Zend_Gdata
 * @subpackage App
 * @copyright  Copyright (c) 2005-2011 Zend Technologies USA Inc. (http://www.zend.com)
 * @license    http://framework.zend.com/license/new-bsd     New BSD License
 */
class Zend_Gdata_App_Feed extends Zend_Gdata_App_FeedSourceParent implements Iterator, ArrayAccess, Countable {
	
	/**
	 * The root xml element of this data element
	 *
	 * @var string
	 */
	protected $_rootElement = 'feed';
	
	/**
	 * Cache of feed entries.
	 *
	 * @var array
	 */
	protected $_entry = array ();
	
	/**
	 * Current location in $_entry array
	 *
	 * @var int
	 */
	protected $_entryIndex = 0;
	
	/**
	 * Make accessing some individual elements of the feed easier.
	 *
	 * Special accessors 'entry' and 'entries' are provided so that if
	 * you wish to iterate over an Atom feed's entries, you can do so
	 * using foreach ($feed->entries as $entry) or foreach
	 * ($feed->entry as $entry).
	 *
	 * @param  string $var The property to get.
	 * @return mixed
	 */
	public function __get($var) {
		switch ($var) {
			case 'entries' :
				return $this;
			default :
				return parent::__get ( $var );
		}
	}
	
	/**
	 * Retrieves the DOM model representing this object and all children
	 *
	 * @param DOMDocument $doc
	 * @return DOMElement
	 */
	public function getDOM($doc = null, $majorVersion = 1, $minorVersion = null) {
		$element = parent::getDOM ( $doc, $majorVersion, $minorVersion );
		foreach ( $this->_entry as $entry ) {
			$element->appendChild ( $entry->getDOM ( $element->ownerDocument ) );
		}
		return $element;
	}
	
	/**
	 * Creates individual Entry objects of the appropriate type and
	 * stores them in the $_entry array based upon DOM data.
	 *
	 * @param DOMNode $child The DOMNode to process
	 */
	protected function takeChildFromDOM($child) {
		$absoluteNodeName = $child->namespaceURI . ':' . $child->localName;
		switch ($absoluteNodeName) {
			case $this->lookupNamespace ( 'atom' ) . ':' . 'entry' :
				$newEntry = new $this->_entryClassName ( $child );
				$newEntry->setHttpClient ( $this->getHttpClient () );
				$newEntry->setMajorProtocolVersion ( $this->getMajorProtocolVersion () );
				$newEntry->setMinorProtocolVersion ( $this->getMinorProtocolVersion () );
				$this->_entry [] = $newEntry;
				break;
			default :
				parent::takeChildFromDOM ( $child );
				break;
		}
	}
	
	/**
	 * Get the number of entries in this feed object.
	 *
	 * @return integer Entry count.
	 */
	public function count() {
		return count ( $this->_entry );
	}
	
	/**
	 * Required by the Iterator interface.
	 *
	 * @return void
	 */
	public function rewind() {
		$this->_entryIndex = 0;
	}
	
	/**
	 * Required by the Iterator interface.
	 *
	 * @return mixed The current row, or null if no rows.
	 */
	public function current() {
		return $this->_entry [$this->_entryIndex];
	}
	
	/**
	 * Required by the Iterator interface.
	 *
	 * @return mixed The current row number (starts at 0), or NULL if no rows
	 */
	public function key() {
		return $this->_entryIndex;
	}
	
	/**
	 * Required by the Iterator interface.
	 *
	 * @return mixed The next row, or null if no more rows.
	 */
	public function next() {
		++ $this->_entryIndex;
	}
	
	/**
	 * Required by the Iterator interface.
	 *
	 * @return boolean Whether the iteration is valid
	 */
	public function valid() {
		return 0 <= $this->_entryIndex && $this->_entryIndex < $this->count ();
	}
	
	/**
	 * Gets the array of atom:entry elements contained within this
	 * atom:feed representation
	 *
	 * @return array Zend_Gdata_App_Entry array
	 */
	public function getEntry() {
		return $this->_entry;
	}
	
	/**
	 * Sets the array of atom:entry elements contained within this
	 * atom:feed representation
	 *
	 * @param array $value The array of Zend_Gdata_App_Entry elements
	 * @return Zend_Gdata_App_Feed Provides a fluent interface
	 */
	public function setEntry($value) {
		$this->_entry = $value;
		return $this;
	}
	
	/**
	 * Adds an entry representation to the array of entries
	 * contained within this feed
	 *
	 * @param Zend_Gdata_App_Entry An individual entry to add.
	 * @return Zend_Gdata_App_Feed Provides a fluent interface
	 */
	public function addEntry($value) {
		$this->_entry [] = $value;
		return $this;
	}
	
	/**
	 * Required by the ArrayAccess interface
	 *
	 * @param int $key The index to set
	 * @param Zend_Gdata_App_Entry $value The value to set
	 * @return void
	 */
	public function offsetSet($key, $value) {
		$this->_entry [$key] = $value;
	}
	
	/**
	 * Required by the ArrayAccess interface
	 *
	 * @param int $key The index to get
	 * @param Zend_Gdata_App_Entry $value The value to set
	 */
	public function offsetGet($key) {
		if (array_key_exists ( $key, $this->_entry )) {
			return $this->_entry [$key];
		}
	}
	
	/**
	 * Required by the ArrayAccess interface
	 *
	 * @param int $key The index to set
	 * @param Zend_Gdata_App_Entry $value The value to set
	 */
	public function offsetUnset($key) {
		if (array_key_exists ( $key, $this->_entry )) {
			unset ( $this->_entry [$key] );
		}
	}
	
	/**
	 * Required by the ArrayAccess interface
	 *
	 * @param int $key The index to check for existence
	 * @return boolean
	 */
	public function offsetExists($key) {
		return (array_key_exists ( $key, $this->_entry ));
	}
	
	/**
	 * Retrieve the next set of results from this feed.
	 *
	 * @throws Zend_Gdata_App_Exception
	 * @return mixed|null Returns the next set of results as a feed of the same
	 * class as this feed, or null if no results exist.
	 */
	public function getNextFeed() {
		$nextLink = $this->getNextLink ();
		if (! $nextLink) {
			require_once 'Zend/Gdata/App/HttpException.php';
			throw new Zend_Gdata_App_Exception ( 'No link to next set ' . 'of results found.' );
		}
		$nextLinkHref = $nextLink->getHref ();
		$service = new Zend_Gdata_App ( $this->getHttpClient () );
		
		return $service->getFeed ( $nextLinkHref, get_class ( $this ) );
	}
	
	/**
	 * Retrieve the previous set of results from this feed.
	 *
	 * @throws Zend_Gdata_App_Exception
	 * @return mixed|null Returns the previous set of results as a feed of
	 * the same class as this feed, or null if no results exist.
	 */
	public function getPreviousFeed() {
		$previousLink = $this->getPreviousLink ();
		if (! $previousLink) {
			require_once 'Zend/Gdata/App/HttpException.php';
			throw new Zend_Gdata_App_Exception ( 'No link to previous set ' . 'of results found.' );
		}
		$previousLinkHref = $previousLink->getHref ();
		$service = new Zend_Gdata_App ( $this->getHttpClient () );
		
		return $service->getFeed ( $previousLinkHref, get_class ( $this ) );
	}
	
	/**
	 * Set the major protocol version that should be used. Values < 1 will
	 * cause a Zend_Gdata_App_InvalidArgumentException to be thrown.
	 *
	 * This value will be propogated to all child entries.
	 *
	 * @see _majorProtocolVersion
	 * @param (int|NULL) $value The major protocol version to use.
	 * @throws Zend_Gdata_App_InvalidArgumentException
	 */
	public function setMajorProtocolVersion($value) {
		parent::setMajorProtocolVersion ( $value );
		foreach ( $this->entries as $entry ) {
			$entry->setMajorProtocolVersion ( $value );
		}
	}
	
	/**
	 * Set the minor protocol version that should be used. If set to NULL, no
	 * minor protocol version will be sent to the server. Values < 0 will
	 * cause a Zend_Gdata_App_InvalidArgumentException to be thrown.
	 *
	 * This value will be propogated to all child entries.
	 *
	 * @see _minorProtocolVersion
	 * @param (int|NULL) $value The minor protocol version to use.
	 * @throws Zend_Gdata_App_InvalidArgumentException
	 */
	public function setMinorProtocolVersion($value) {
		parent::setMinorProtocolVersion ( $value );
		foreach ( $this->entries as $entry ) {
			$entry->setMinorProtocolVersion ( $value );
		}
	}

}
